Last month's execution of two Chinese missionaries by Islamic State (IS) militants in Pakistan put the risks of such work into stark relief but two young Chinese Christians who have lived close to an IS stronghold in northern Iraq for more than a year said life could be more peaceful there than back at home.

The South China Morning Post obtained an exclusive interview with the couple, who live in a guarded compound that serves as a refuge for women and children who have fled IS persecution.

Michael, 25, and Christy, 23, left China just over a year ago, right after their wedding, for one of the world's most war-torn areas. Security concerns, in Iraq and in China, mean details of their identities cannot be revealed.

"It is not as torn up by warfare here as much as outsiders would read in the news, I actually feel safer here," said Michael, comparing his experience in Iraq with life in China as a full-time worker in an underground Christian church. "Life could be described as normal here."

There are no official statistics about the number of Chinese missionaries working overseas, and they often pose as businessmen or teachers for travel purposes. But estimates by some academics and mainland house churches say there could be hundreds, or even a couple of thousand.

Pastors working on the mainland say it has the largest number of born-again Christians in the world, and that despite having a communist government that is officially atheist is on track to be the world's largest exporter of Christian faith.

Emulating the Western missionaries who proselytised in China centuries ago, most Chinese missionaries serve in developing countries, especially Muslim ones, where such activities are dangerous.

The dream honeymoon destination for most Chinese couples would be somewhere like the Maldives, but Michael and Christy, a former make-up artist, spent their honeymoon and first wedding anniversary in an Iraqi village, saying they were simply called by faith.